It's easy to see why texting or even talking on the phone would be dangerous while behind the wheel — doing so requires you to hold a phone and possibly even take your eyes off the road. But driving hands free allows you to operate the car normally, so it seems like it would be fine. But the trouble is that using technology isn't just dangerous because it occupies your hands or your eyes; it also pulls your focus away from the road as well.

"The lasting effects of mental distraction pose a hidden and pervasive danger that would likely come as a surprise to most drivers," Peter Kissinger, President and CEO of the AAA Foundation for Traffic Safety, said in a statement. "The results indicate that motorists could miss stop signs, pedestrians and other vehicles while the mind is readjusting to the task of driving."

Because it doesn't matter if both your hands are on the wheel and your eyes are straight ahead if your mind is elsewhere.

Even more concerning, when researchers rated various voice-command systems in 10 cars from the 2015 model year they found three to be "moderately distracting," six to be "highly distracting," and one (the 2015 Mazda 6) to be "very highly distracting."

In other words, even though these systems are advertised as safe alternatives to using your phone, the science says otherwise. And, interestingly, the research suggests that the amount of distraction people experience using hands-free devices doesn't decrease over time. People don't in fact get used to the devices and then become less distracted. Based on this research it seems the distraction is an inherent part of using hands-free technology.

Presumably using hands-free devices are better than texting behind the wheel, but it seems that such technology is still best used sparingly, if at all. Basically, if you really want to be safe while driving, the best thing to do is not multitask at all and instead just, well, drive.